This engine was patented by Washburn Race of Lockport, New York. Race was his surname and there is no suggestion that this engine was intended for any form of racing.

In Fig 1, D is the steam inlet pipe. C is a hollow shaft through which the steam exhausts.

From US Patent 116,352 granted 27 June 1871

"The sector pistons are each connected through central concentric shafts to slotted cranks in which a sliding box and link connect to a crank on a shaft eccentric to the sector shaft. A differential movement of the sectors is produced while rotating which rotates the driven shaft by the outside slotted crank connections."

An example of the "pursuing pistons" approach to rotary engine design. Reuleaux says, that as a consequence of the large area between the outer surface of the pistons and the inside of the cylinder, "The joint between piston and chamber can without difficulty be made steam-tight,..."

From "Mechanical Movements, Devices and Appliances" Hiscox, 1899

This is another eccentric-cylinder rotary engine relying on a line seal to remain steam-tight. Two such cylinders were arranged at 180 degrees to give a smoother output torque.

The steam inlet and exhaust passages could be swopped over by the valve G so the engine was reversible.

From US patent 122,713 granted Jan 1872

This engine was patented by Levi M Shaw And Allen S Baker of Evansville, Wisconsin. It is not really a rotary engine so much as a "disc engine".

The output shaft is F. The patent text claims that the output torque is constant.

From US patent 143,723 granted Oct 1873

Here we learn that the Shaw & Baker engine was abandoned due to its poor efficiency, the fate of most rotary engines.

From A Field Guide to American Windmills by T Lindsay Baker. University of Oklahoma Press, 1 Jan 1985

This engine was put forward by Dexter D Hardy of Delavan, Illinois.

The patent model shown here is made of wood; it is not clear if it could be disassembled to reveal the inner workings, but if not it would appear to be of little use.

We have met Dexter D Hardy before, in 1859 and 1868, patenting engnes that were quite different in principle from each other. His next attempt is completely different again.

The patent text is obscure even by the usual standards of rotary engine patents. Steam enters through an axial bore in the central shaft and passes through the ports g. There are two pairs of pistons labelled I joined together by rigid rods. These move in and out, and are eccentrically mounted on the output shaft, which is in some way caused to rotate.

From US patent 141,436 of Aug 1873

This engine comes from Dublin, Ireland. The inventor claims that it is the first single-cylinder rotary engine with no dead-point, ie no dead-centre position where it will not move when steam is applied. This seems highly unlikely.

Secondly he appears to claim that constant torque is obtained whether the engine is run expansively or not; this seems doubtful but his explanation of the steam flow is too obscure for any judgment to be made.

There is no menton of a patent, which is unusual. Charles E Moss and his engine are unknown to Google.

Thanks to Paul Burke for drawing this engine to my attention.

From English Mechanic and World of Science 1875